Autoinjector with deactivating means moveable by a safety shield

ABSTRACT

The invention relates to an injection device ( 1 ) being in one of a passive and active state, triggering of injection being prevented when said device ( 1 ) is in its passive state and permitted when said device ( 1 ) is in its active state, having:
         a housing ( 30, 30   a   , 30   b ) receiving a container, the container being in one of a passive state and an active state, movement of the container out of its initial position being prevented when the container is in its passive state, and being permitted when the container is in its active state, and   a safety shield ( 40 ) coupled with the housing ( 30 ) and being movable with respect to the housing along a movement path having a predetermined length,   first retaining means ( 60, 61, 54   a ) for maintaining the container ( 20 ) in its passive state,   second retaining means ( 34   a   , 81   b ) for maintaining said device ( 1 ) in its passive state,   said device ( 1 ) being characterized in that it comprises:   first deactivating means ( 50, 53 ) and second deactivating means ( 50, 50   a ) movable coincident with movement of the safety shield ( 40 ) so as to place the container ( 20 ) in the active state, and the device ( 1 ) in its active state.

The present invention relates to a device for automatic injection of aproduct in a very safe way, especially for self-injection.

In this application, the distal end of a component or of a device is tobe understood as meaning the end furthest from the user's hand and theproximal end is to be understood as meaning the end closest to theuser's hand. Likewise, in this application, the “distal direction” is tobe understood as meaning the direction of injection, and the “proximaldirection” is to be understood as meaning the opposite direction to thedirection of injection.

Some illnesses necessitate regular injections of drugs or products, forinstance on a daily basis. In order to simplify the treatment, someself-injectors have been provided in order to allow the patient toperform the injection on its own.

Of course, since the patient is usually neither a nurse nor an educatedperson in medical devices, such self-injectors must prove to be verysimple to use and also very safe. In particular, the insertion of theneedle must be performed at the right depth, the correct dose of productmust be injected, that is to say a complete injection must be performed,and the injector must be deactivated after use before it is disposed of.Preferably, the needle should not be exposed, before and after use, inorder to prevent any accidental needlestick injury.

An important requirement of these self-injection devices is that theymust not be able to be activated inadvertently, before the patient isready to perform the injection, and in particular before the device iscorrectly applied at the right injection site.

Injections devices provided with safety systems preventing thetriggering of the insertion of the needle as long as the device is notcorrectly positioned on the patient's skin have been described.

In some cases though, because the operation of self-injecting a productmay be stressful for the user and also because it requires that a highforce be applied on the skin at the injection site, the user may,inadvertently or not, displace the self-injection device on the skin,after having triggered the insertion of the needle but before theinjection has started. If the injection device is provided with a safetysystem that covers the needle on displacement or removal of theinjection device, the injection device is not usable anymore and themedicinal product is lost.

There is therefore a need for an injection device, in particular forautomatic injection, that would reduce the force with which theinjection device is to be applied on the skin and that would minimizethe risks related to a misuse of the injection device by a non educatedperson in medical devices.

The present invention meets this need by proposing a device forautomatic injection of a product into an injection site, said devicecomprising a safety system that allows a safe and efficient injection,even if the user moves and/or removes the device from the skin once hehas triggered the insertion of the needle.

The present invention relates to a device for automatic injection of aproduct into an injection site, said device being in one of a passiveand active state, triggering of injection being prevented when saiddevice is in its passive state and permitted when said device is in itsactive state, said device having:

a housing capable of receiving a container, the container being movablerelative to the housing between an initial position and an insertionposition distally spaced from the initial position, the container beingin one of a passive state and an active state, movement of the containerout of its initial position being prevented when the container is in itspassive state, and being permitted when the container is in its activestate, and

a safety shield coupled with the housing and being movable with respectto the housing along a movement path having a predetermined length, thesafety shield being movable between a first position and a secondposition a first distance that is less than the predetermined length,and between the second position and a third position a second distancethat is less than the predetermined length,

first retaining means for maintaining the container in its passivestate,

second retaining means for maintaining said device in its passive state,

said device being characterized in that it further comprises:

first deactivating means movable coincident with movement of the safetyshield the first distance to cooperate with first retaining means so asto place the container in the active state, and

second deactivating means movable coincident with movement of the safetyshield the second distance to cooperate with second retaining means soas to place the device in its active state.

The device of the invention is very simple to use. Moreover, as willappear more clearly from the description below, the device of theinvention allows a complete and safe injection even if the user mis usesthe device and performs mistakes during the use of the device. Inparticular, in case the user mis-uses the device of the invention, thenthe product is not lost and the injection may be correctly and safelycompleted in the end.

In an embodiment of the invention, part of the first and seconddeactivating means are formed on a sleeve coupled to the safety shieldand being received within said housing, the sleeve being movable inrotation and in translation with respect to the housing when the safetyshield moves from its first position to its second position, the sleevebeing movable in translation with respect to the housing when the safetyshield moves from its second position to its third position.

In an embodiment of the invention, said first retaining means comprisesa ring coupled with the housing, the ring comprising at least one outerradial stop,

the first deactivating means comprises a window defined in the sleeveand having an abutment surface,

the outer radial stop being engageable with the abutment surface whenthe safety shield is in its first position, and being disengageable fromthe abutment surface when the safety shield is moved from its firstposition to its second position.

In an embodiment of the invention:

the second retaining means comprises a radially deflectable leg coupledto the housing,

the second deactivating means comprises a projection, defined at aproximal end of said sleeve, the projection being capable of deflectingthe radially deflectable leg from a rest position, in which the radiallydeflectable leg maintains the device in its passive state, to adeflected position, in which the device is in its active state,deflection of the radially deflectable leg from its rest position to itsdeflected position being caused by movement of the safety shield fromits second position to its third position.

In an embodiment of the invention, the device further comprises firstguiding means for causing the translational and rotational movement ofthe sleeve when the safety shield is moved from its first position toits second position, and second guiding means for causing thetranslational movement of the sleeve with respect to the housing whenthe safety shield is moved from its second position to its thirdposition, the second guiding means preventing the rotation of he sleevewith respect to the housing as the safety shield is moved to its thirdposition.

In an embodiment of the invention, the first guiding means defines thefirst distance, and wherein the second guiding means defines the seconddistance.

In an embodiment of the invention, said first guiding means includes apeg located on the sleeve or on the housing and a first portion of a camlocated respectively on the housing or on the sleeve and in which thepeg is engaged so as to be able to move slidingly within the cam, thefirst portion of the cam being inclined with respect to the longitudinalaxis of the device, movement of the peg within the first portion of thecam causing translational and rotational movement of the sleeve when thesafety shield is moved from its first position to its second position.

In an embodiment of the invention, the second guiding means include asecond portion of the cam, the second portion being longitudinal, thejunction of the first and said second portions of the cam forming anelbow, the movement of the peg within the second portion of the camcausing translational movement of the sleeve when the safety shield ismoved from its second position to its third position.

In an embodiment of the invention, the device further comprises:

first biasing means coupled to the housing for biasing the containertoward the insertion position, the first biasing means being in one of acompressed condition, in which the container is in its initial position,and an extended condition, in which the container is in its insertionposition, and

third retaining means for maintaining the first biasing means in itscompressed condition,

triggering means being user activatable for releasing the thirdretaining means, once the device is in its active state.

In an embodiment of the invention, the device comprises return means forbiasing the safety shield from its third position to its second positionafter activation of the triggering means but before the containerreaches its insertion position, the second guiding means causing thesleeve to move translationally in the distal direction with respect tothe housing until the peg comes in abutment with the elbow formed at thejunction between the first portion and second portion of the cam.

In an embodiment of the invention, said return means comprise a springin a compressed condition when the safety shield is in its thirdposition.

In an embodiment of the invention, the device further comprises lockingmeans for preventing the sleeve to rotate back with respect to thehousing under the effect of said return means, the locking meanscomprising a rotational stop located on the sleeve or on the housing,the rotational stop being engaged in abutment against a longitudinalridge located on the housing or respectively on the sleeve, therebypreventing the rotation of the sleeve with respect to the housing.

In an embodiment of the invention:

the safety shield being movable with respect to the container from itsthird position, in which the tip of the needle does not extend beyond adistal end of the safety shield, to a fourth position, in which the tipof the needle extends beyond a distal end of the safety shield, and to afifth position, in which the tip of the needle does not extend beyond adistal end of the safety shield, movement of said safety shield from itsfourth position to its fifth position being caused by release of adistal pressure exerted on said housing,

said device further comprises

arresting means for maintaining the safety shield in its third position,in which the release of the distal pressure exerted on said housing doesnot cause the safety shield to move to its fifth position,

third deactivating means designed for deactivating the arresting meanswhen the safety shield is in its fourth position

second biasing means coupled to the safety shield for biasing the safetyshield from its fourth position to its fifth position when distalpressure exerted on the housing is released.

In an embodiment of the invention, the arresting means comprises aflexible leg located on the safety shield, the flexible leg beingengaged on an abutment surface located on the sleeve so as to maintainthe sleeve coupled to the safety shield when the safety shield is in itsthird position.

In an embodiment of the invention, the ring being coupled to thecontainer,

the third deactivating means comprises a distal skirt located on thering, the distal skirt cooperating with the flexible leg located on thesafety shield so as to deflect the flexible leg, when the containermoves from its initial position to its insertion position, therebycausing the safety shield to be in its fourth position.

The invention and its advantages will appear more clearly in the lightof the following description and the annexed drawing in which:

FIG. 1 is an exploded perspective view of a device according to theinvention,

FIG. 2 is a cross section view of the device of FIG. 1 as provided to auser before use,

FIG. 3 is a cross section view, taken after a rotation of 90° of thedevice of FIG. 2,

FIGS. 4 and 5 are perspective views of the device of FIGS. 2 and 3 withthe housing taken out,

FIG. 6 is a partial side view of the housing and the sleeve of thedevice of FIGS. 1-5,

FIG. 7 is a cross section view of the device of FIG. 1 after removal ofthe needle shield,

FIG. 8 is a cross section view, taken after a rotation of 90° of thedevice of FIG. 7,

FIG. 9 is a partial side view of the housing and the sleeve of thedevice of FIGS. 1-8 after removal of the needle shield,

FIG. 10 is a partial perspective view of the housing and the sleeve ofthe device of FIGS. 1-9 after removal of the needle shield,

FIG. 11 is a cross section view of the device of FIGS. 1-10 with thesafety shield in its second position,

FIG. 12 is a cross section view, taken after a rotation of 90° of thedevice of FIG. 11,

FIG. 13 is a partial cross section view, taken after a slight rotationof the device of FIG. 11,

FIGS. 14 and 15 are perspective views of the device of FIGS. 11-13 withthe housing taken out,

FIG. 16 is a partial side view of the housing and the sleeve of thedevice of FIGS. 1-15 when the safety shield is in its second position,

FIG. 17 is a partial perspective view of the housing and the sleeve ofthe device of FIGS. 1-16 when the safety shield is in its secondposition,

FIG. 18 is partial cross section view of the device of FIGS. 1-17 whenthe safety shield is in its third position,

FIG. 19 is a cross section view, taken after a rotation of 90° of thedevice of FIG. 18,

FIG. 20 is a partial cross section view, taken after a slight rotationof the device of FIG. 18,

FIGS. 21 and 22 are perspective views of the device of FIGS. 18-20 withthe housing taken out,

FIG. 23 is a partial side view of the housing and the sleeve of thedevice of FIGS. 1-22 when the safety shield is in its third position,

FIG. 24 is a partial cross section view of the device of FIGS. 1-23after activation of the triggering means,

FIG. 25 is a cross section view, taken after a rotation of 90° of thedevice of FIG. 24,

FIG. 26 is a partial cross section view, taken after a slight rotationof the device of FIG. 24,

FIGS. 27 and 28 are perspective views of the device of FIGS. 24-26 withthe housing taken out,

FIG. 29 is a partial cross section view of the device of FIGS. 1-27 atthe end of injection,

FIG. 30 is a cross section view, taken after a rotation of 90° of thedevice of FIG. 29,

FIG. 31 is a partial cross section view, taken after a slight rotationof the device of FIG. 29,

FIG. 32 is a partial cross section view of the device of FIGS. 1-27 atthe end of injection in case of misuse of the device,

FIG. 33 is a cross section view, taken after a rotation of 90° of thedevice of FIG. 32,

FIG. 34 is a partial cross section view, taken after a slight rotationof the device of FIG. 32,

FIG. 35 is a partial cross section view of the device of FIGS. 1-34 whenthe safety shield is in its fifth position,

FIG. 36 is a cross section view, taken after a rotation of 90° of thedevice of FIG. 35,

FIG. 37 is a partial cross section view, taken after a slight rotationof the device of FIG. 35,

FIGS. 38 and 39 are perspective views of the device of FIGS. 35-37 withthe housing taken out.

Referring now to the drawings, on FIG. 1 is shown an exploded view of adevice 1 according to the invention for automatic injection of aproduct.

With reference to FIGS. 1 and 2, the device 1 comprises a container 20having an open proximal end 20 a and a substantially closed distal end,said container 20 being intended to receive a product 2 to be injectedat an injection site 4 (see FIG. 11). The distal end of the container 20is covered on FIG. 1 by a needle cap 21 in view of protecting a needle 3provided at said distal end. As can be seen on FIG. 2, a piston 5 islodged within said container 20, the distal movement of the piston 5causing the product 2 to be expelled via the needle 3 at the time ofinjection. The device 1 has a longitudinal axis designated by the letterA on the figures.

The device 1 further comprises a housing 30 comprising a top body 30 aand a bottom body 30 b, said top and bottom bodies being coupledtogether after assembly of the device as shown on FIG. 2. As will appearhereinbelow, the housing 30 is intended to receive the container 20,said container 20 being movable relative to the housing 30 between aninitial position (shown on FIGS. 7 and 8) to an insertion position(shown on FIGS. 24-25 and 29-30).

As appears more clearly from FIGS. 2 and 3, the top body 30 a comprisesan inner cylinder 32 provided with a radial rim 31 and with flexiblelegs 33. The inner cylinder 32 is also provided at its distal end withouter flexible tongues 34 extending in the proximal direction and havingproximal ends 34 a.

As shown on FIG. 3, the bottom body 30 b is provided on its inner wallwith radial projections 35.

In reference with FIGS. 1 and 6, the bottom body 30 b is provided in itsproximal region with a cam 36 and a window 37, the window 37 beingdistally spaced from the cam 36. The cam 36 is formed in its distalregion of a first portion 36 a and in its proximal region of a secondportion 36 b. The first portion 36 a is inclined with respect to alongitudinal axis A of the device 1. The second portion 36 b islongitudinal. The junction of the first and second portions (36 a, 36 b)of the cam 36 forms an elbow 36 c.

The window 37 has a generally rectangular shape with a longitudinal axisparallel to the longitudinal axis of the device 1.

As better seen on FIG. 10, the bottom body 30 b is provided on its innerwall with a longitudinal ridge 38.

The device 1 further comprises a safety shield 40: the safety shield 40is received within the housing 30 and is movable with respect to saidhousing 30 as will appear later. The safety shield 40 is provided withproximal flexible legs 41. The proximal flexible legs 41 are providedwith proximal inclined surfaces 41 a and distal radial abutment surfaces41 b. The proximal region of the safety shield 40 is also provided withflexible tongues 42 extending in the outward direction. The safetyshield 40 is further provided with an inner radial rim 43 (see FIG. 2).

The device 1 further comprises a sleeve 50. The sleeve 50 is provided atits proximal end with a projection 50 a and at its distal end on itsinner wall with a circumferential ridge 51 having a proximal abutmentsurface 51 a (see FIG. 2). With reference to FIGS. 4 and 5, in itsproximal region, the sleeve 50 is provided on its outer wall with a peg52. The sleeve 50 is further provided with a first window 53 distallyspaced from the peg 52 and having a substantially rectangular shape, thelongitudinal axis of said first window 53 being parallel to thelongitudinal axis A of the device 1. On one lateral wall of said firstwindow 53 is located a recess 54 forming an abutment surface 54 a.Tangentially spaced from the peg 52 is cut in the wall of the sleeve 50a second window 55 in which a flexible tongue 56 is located, saidflexible tongue 56 extending in the circumferential direction. The freeend of said flexible tongue 56 is provided with a projection 57.

The device 1 further comprises a ring 60 received between the container20 and the sleeve 50. The ring 60 comprises two radial stops 61extending outwardly. The ring 60 is also provided with a skirt 62extending distally.

The device 1 comprises a piston rod 70 and a push button 80. As shown onFIGS. 1-3, the piston rod 70 is provided at its distal end with an outerrim 71 and at its proximal end with an abutment rim 72. The push button80 is provided with two distal legs 81 having distal ends 81 b. The pushbutton 80 is also provided with two inner legs 82 extending from theproximal end of the push button 80 and visible on FIG. 3.

At its distal end, the device 1 is further provided with a deshielder 90intended to cover and to be coupled to the needle shield 21 before use.

The device 1 is further provided with two helical springs. A firsthelical spring 100 is received between the piston rod 70 and the pushbutton 80. A second helical spring 110 is received between the container20 and the safety shield 40.

With reference to FIGS. 2 to 6, the device 1 is in the state in which itis provided to the user. As can be seen on FIG. 6, in this position, theouter radial stop 61 of the ring 60 protrudes through both the window 37of the bottom body 30 b of the housing 30 and the first window 53 of thesleeve 50. In this position also, the peg 52 of the sleeve is located inthe distal end of the first portion 36 a of the cam 36 of the bottombody 30 b of the housing 30.

The operation of the device 1 according to the invention will now bedescribed in reference to FIGS. 2 to 39.

Once the user is ready to use the device 1 of the invention, he removesthe deshielder 90 as shown on FIGS. 7 and 8. By removing the deshielder90, he also removes the needle shield 21, and the device 1 is ready tobe used. As appears from FIGS. 7 and 8, after removal of the deshielder90, the distal end 40 a of the safety shield 40 protrudes out of thebottom body 30 b of the housing.

In this ready to use position, the container 20 is in its initialposition. As can be seen from FIGS. 7 and 8, the tip 3 a of the needle 3extends neither beyond the distal end of the bottom body 30 b of thehousing 30 nor beyond the distal end 40 a of the safety shield 40.

On FIGS. 7-9, the container 20 is also in a passive state: indeed, theremoval of the deshielder 90 has allowed the ring 60 to move distallywith respect to the sleeve 50 on a short distance until its outer radialstops 61 come in abutment against the abutment surface 54 a of thewindow 53 of the sleeve 50, as shown on FIG. 9. In consequence, in thisready to use position, movement of said container 20 out of its initialposition is prevented by means of the radial stops 61 of the ring 60being in abutment on the abutment surface 54 of the first window 53 ofthe sleeve 50. The radial stops 61 of the ring 60 act as first retainingmeans for maintaining the container 20 in its passive state.

As shown on FIG. 7, in the ready to use position of the device 1, thedistal end 81 b of the distal leg 81 of the push button 80 faces theproximal end 34 a of the outer flexible tongue 34 of the inner cylinder32 of the top body 30 a. In consequence, if a user wishes to push on thepush button 80, the distal movement of the push button 80 is restrictedby way of leg 81 coming in abutment against the proximal end 34 a of theflexible tongue 34 and the triggering of the injection is not permitted.The device 1 is therefore in a passive state, and the distal end 81 b ofthe distal leg 81 and the proximal end 34 a of the flexible 34 act assecond retaining means for maintaining the device 1 in a passive state.

Still with reference to FIGS. 7 and 8, the flexible legs 33 of the innercylinder 32 of the top body 30 a are engaged in the abutment rim 72 ofthe piston rod 70.

In the ready to use position, as shown on FIGS. 7 and 8, the proximalend of the first spring 100 bears on the radial rim 31 located on theinner cylinder 32 of top body 30 a. The distal end of the first spring100 bears on the outer rim 71 provided at the distal end of the pistonrod 70. On these figures and in this ready to use position of the device1, the first spring 100 is in a compressed condition. The radial rim 31and the outer rim 71 on one hand, and the flexible legs 33 and theabutment rim 72 on the other hand, act as third retaining means formaintaining the first spring 100 in its compressed condition.

On these figures, the distal end of the second spring 110 bears on theproximal face of the inner radial rim 43 provided on the inner wall ofthe safety shield 40, and the proximal end of the second spring 110bears on an inner abutment surface 63 located on the ring 60. In thebefore use position of the device 1, the spring 110 is in a partiallycompressed condition.

In the ready to use position shown on FIGS. 7 and 8, the safety shield40 is coupled to sleeve 50 by means of the distal radial abutmentsurfaces 41 b of the safety shield 40 being engaged on the proximalabutment surface 51 a of the sleeve 50. The safety shield is in itsfirst position.

In order to proceed with the injection, the container 20 must be placedin its active state. In this view, the user grabs the device 1 by thehousing 30 formed of the top body 30 a and the bottom body 30 b and heapplies the distal end of the device 1, namely the distal end 40 a ofthe safety shield 40 on the site of injection 4 as shown on FIGS. 11 and12. He then applies a distal force on the housing 30, for instance viathe top body 30 b, which causes the safety shield 40 to move in theproximal direction with respect to the housing 30. The sleeve 50 beingcoupled to the safety shield 40, the proximal movement of the safetyshield 40 has the consequence to cause the movement of the peg 52 in thefirst portion 36 a of the cam 36 of the bottom body 30 b of the housing30 as shown on FIGS. 16 and 17. The movement of the peg 52 in theinclined first portion 36 a of the cam 36 causes the bottom body 30 b ofthe housing 30 to rotate with respect to the sleeve 50. Since the ring60 is engaged in the window 37 of the bottom body 30 b via the radialstops 61 extending through said window 37, the ring 60 is coupled withthe housing 30 and drawn with the bottom body 30 b: in consequence, thering 60 also rotates with respect to the sleeve 50: with this movement,the radial stops 61 of the ring 60 disengage from the abutment surface54 a of the first window 53 of the sleeve 50, as shown on FIGS. 14 and16. This has the consequence of putting the container 20 in its activestate, movement of said container 20 out of its initial position beingno more prevented by the ring 60 being in abutment against the abutmentsurface 54 c. Moreover, the safety shield 40 is now in its secondposition.

During the movement of the safety shield 40 from its first position toits second position as described above, the peg 52 and the first portion36 a of the cam 36 have acted as first guiding means for causing thetranslational and rotational movement of the sleeve 50. In analternative embodiment of the device of the invention not shown, the pegis located on the housing and the cam is located on the sleeve.

The safety shield 40 has moved from its first position to its secondposition along a first distance D1 represented on FIG. 16. During thisstep, the sleeve 50 and its window 53 have moved coincident with themovement of the safety shield 40 on said first distance D1 so as to actas first deactivating means of the first retaining means, namely theouter radial stop 61 of the ring 60, and place the container 20 in itsactive state.

As shown on FIG. 17, during the rotation of the sleeve 50 with respectto the bottom body 30 b of the housing 30, the flexible tongue 56 hasalso rotated with respect to the bottom body 30 b and has overcome thelongitudinal ridge 38 of the bottom body 30 b. As appears on FIG. 17,the projection 57 of the flexible tongue 56 is now in abutment againstthe longitudinal ridge 38 therefore preventing any rotation back of thesleeve 50 with respect to the bottom body 30 b of the housing 30. Thefunction of said projection as such rotational stop will be explainedlater.

Due to the advantageous design of the present invention, a user needonly use minimal force when applying the device 1 against his or herskin. To cause the safety shield 40 to rotate and move in the proximaldirection and place the container 20 in the active state, the userapplies the device 1 against his or her skin, and with a low force,causes the safety shield 40 to move in the proximal direction.

The container 20 is now in its active state. In this position, as shownon FIG. 13, the distal end 81 b of the distal leg 81 of the push button80 still faces the proximal end 34 a of the flexible tongue 34 of theinner cylinder 32 of top body 30 a of the housing 30. Distal movement ofthe push button 80 is therefore still restricted by the distal end 81 bof distal leg 81 coming in abutment against the proximal end 34 a of theflexible tongue 34 and the device 1 is therefore still in its passivestate.

The user then continues to apply a small distal force on the housing 30and in the same way as described above, since the safety shield 40 isstill coupled to the sleeve 50 by means of flexible legs 41 beingengaged in proximal abutment surface 51 a of the sleeve, this causes thepeg 52 to further move within the cam 36 of the bottom body 30 b of thehousing 30, this time within the second portion 36 b of said cam 36, asshown on FIG. 17. This further movement of the peg 52 within thelongitudinal second portion 36 b of the cam 36 causes this time onlyproximal translation of the sleeve 50 with respect to the top body 30 aof the housing 30. As shown on FIGS. 18 and 20, the projection 50 a atthe proximal end of the sleeve 50, by proximally translating withrespect to the top body 30 a, now pushes on the flexible tongue 34 ofthe top body 30 a, thereby deflecting said flexible tongue 34 inwardly.As a consequence, the proximal end 34 a of the flexible tongue 34 isdriven away from the distal end 81 b of the distal leg 81 of the pushbutton 80. In consequence, the distal movement of the push button 80 isnow allowed and by consequence, triggering of the injection is also nowallowed. The device 1 is now in its active state. During this movement,once the peg 52 has reached the proximal end of the second portion 36 bof the cam 36, as shown on FIG. 23, the safety shield 40 has moved toits third position.

In the step described above, the second portion 36 ab of the cam 36 actsas second guiding means for causing the translational movement of thesleeve 50 with respect to the housing 30 when the safety shield 40 ismoved from its second position to its third position. Since thedirection of the second portion 36 b of the cam is only longitudinal,the second portion 36 b of the cam 36 prevents the rotation of thesleeve 50 with respect to the housing 30 as the safety shield is movedto its third position.

The safety shield 40 has moved from its second position to its thirdposition along a second distance D2 represented on FIG. 23. During thisstep, the sleeve 50 and the projection 50 a at its proximal end havemoved coincident with the movement of the safety shield 40 on saidsecond distance D2 so as to act as second deactivating means of thesecond retaining means, namely the proximal end 34 a of the flexibletongue 34, and place the device 1 in its active state.

During the steps described above, the second spring 110 has beenslightly compressed with respect to its initial condition.

The FIGS. 18-23 show the injection device 1 with both the container 20and the device 1 in their respective active state.

The force needed by the user in order to apply the device 1 on theinjection site and in order to move the safety shield 40 with respect tothe housing 30 as described above is very low, in particular becausepart of the various deactivation of the retaining means is obtained byrotation of the intermediate sleeve 50 with respect to the housing 30.The device 1 is therefore very simple to use for the user.

With reference to FIGS. 24-28, the device 1 being now in its activestate, the injection step as such may now be triggered by pushingdistally on the pushing surface 80 a of the push button 80.

With reference to FIG. 25, by pushing distally on the push button 80,the inner legs 82 of the push button 80 deflect the flexible legs 33 ofthe top body 30 a and therefore free the spring 100 which extends in thedistal direction in view of returning to an uncompressed condition. Byextending, the spring 100 draws with him the container 20 which, becauseit is in its active state, is allowed to move distally, thereby causingthe penetration of the needle 3 in the injection site 4. As shown onFIGS. 24, 25 and 27 and 28, the tip 3 a of the needle 3 now extendsbeyond the distal end 40 a of the safety shield 40 and the properinjection of the product 2 contained in the container 20 can take place.

During the insertion step just described, the second spring 110 has beencompressed, as shown on FIGS. 24 to 26, due to the distal movement ofthe container 20. During this movement, the ring 60 has been drawn bythe container 20 and has moved distally with respect to the sleeve 50until its distal skirt 62 has become inserted between the proximalflexible legs 41 of the safety shield 40 and the sleeve 50, therebydeflecting inwardly said proximal flexible legs 41 and disengaging saidproximal flexible legs 41 from the proximal abutment surface 51 a of thecircumferential ridge 51 of the sleeve 50, as shown on FIGS. 24 and 26.

In the third position of the safety shield 40, the proximal flexiblelegs 41 engaged in the proximal abutment surface 51 a of thecircumferential ridge 51 of the sleeve 50 acted as arresting means formaintaining said safety shield 40 in its third position.

The distal skirt 62 of the ring, by deflecting said flexible legs 41,acts as third deactivating means for deactivating the arresting means.The disengagement of the proximal flexible legs 41 from thecircumferential ridge 51 causes the safety shield 40 to be in a fourthposition, in which the tip 3 a of the needle 3 extends beyond the distalend 40 a of the safety shield 40 and in which distal movement of thesafety shield 40 with respect to the container 20 is allowed uponrelease of distal pressure exerted on the housing 30. In this fourthposition of the safety shield 40, said safety shield 40 is no morecoupled to the sleeve 50.

A case of misuse by the user is the following one: after having done thenecessary as described above in order to put both the container 20 andthe device 1 in their respective active state, the user may begin topush distally on the push button 80 and almost simultaneously hewithdraws the device 1 from the injection site, for example on adistance of 1 mm. Usually, the user will not even notice he haswithdrawn the device from the injection and he will carry on applying aforce on the push button. In devices of the prior art, in such a case,the push button is allowed to move distally, the spring is freed asdescribed above and the injection is completed although not at the rightinsertion depth. In some devices of prior art comprising a ring such asthe one described above, such ring may then never reach the flexiblelegs 41 and the safety shield 40 is not allowed to extend at the end ofinjection, rendering the device very dangerous.

The device 1 of the present invention shown on FIGS. 1-39 remedies thisproblem. When the container 20 and the device 1 of the invention are intheir respective active state as shown on FIGS. 18 to 20, if the userbegins to push distally on the push button 80, and then withdraws thedevice 1 from the injection site 4 for about 1 mm for example, then thesleeve 50 is only allowed to translate back on the very short distancedefined by the second portion 36 b of the cam 36, that is on distanceD2, but it is not allowed to rotate back because of the projection 57 ofthe flexible tongue 56 of the sleeve 50 being in abutment on thelongitudinal ridge 38 of the bottom body 30 b of the housing 30 (se FIG.17). In consequence, the peg 52 is stuck on the elbow 36 c of the cam 36and the sleeve 50 can not rotate back. In such a configuration, as canbeen easily understood from FIG. 16, the ring 60 remains disengaged fromthe abutment surface 54 a of the first window 53 of the sleeve 50. Inconsequence, because the ring 60 remains disengaged from the abutmentsurface 54 a, when the user continues applying a distal force on thepush button 80, the container 20 is still in its active state and isallowed to move distally: the penetration of the injection site 4 by theneedle 3 takes place and the injection can be completed in a correctway, although the user has misused the device 1 in the first place.

In correct use of the device 1, with reference to FIGS. 29 to 31, theinjection is completed by virtue of first spring 100 acting as a biasingmeans on the piston rod 70 and causing the distal movement of the pistonrod 70 which reaches the piston 5 and pushes said piston 5 distally,thereby causing the product to be expelled via the needle 3. On FIGS. 29to 31, the first spring 100 is in its expanded state, the piston 5 hasreached the distal end of the container 20 and all the product 2 hasbeen expelled.

Moreover, in case of misuse as described above, as can be seen on FIGS.32-34, since the sleeve 50 has moved back on the distance D2corresponding to the length of the second portion 36 b of the cam 36,the ring 60 does not reach the bottom end of the sleeve 50, as it wasthe case in normal use shown on FIG. 24: yet said ring 60 has moveddistally on a sufficient distance with respect to the sleeve 50 in orderto deflect the proximal flexible legs 41 of the safety shield 40, asshown on FIGS. 32 and 34 so as to disengage them from the proximalsurface abutment 51 a of circumferential ridge 51 of the sleeve 50 andtherefore put the safety shield 40 in its fourth position, in which saidsafety shield 40 is no more coupled to said sleeve 50 and in whichdistal movement of said safety shield 40 is allowed upon release ofdistal pressure exerted on said housing 30.

In consequence, at the end of the injection, because of thedisengagement of the flexible legs 41 from the ridge 51, the withdrawalof the device 1 from the injection site causes the distal movement ofthe safety shield 40 drawn by the second spring 110 tending to come backto an extended condition. As shown on FIGS. 35-39, the safety shield 40has moved from its fourth position to its fifth position and it nowcovers the needle 3 and the injection device 1 can be safely handed.

As shown on FIG. 36, the safety shield 40 is now locked in its fifthposition by means of flexible tongues 42 being blocked against theradial projections 35 of the bottom body 30 b in the proximal direction.Indeed, during the distal movement of the safety shield 40 from itsfourth position to its fifth position, the flexible tongues 42, due tothe fact that they extend in the outward direction, have been able toovercome the radial projections 35.

The radial projections 35 now act as a stop and prevent the proximalmovement of the safety shield 40 with respect to the container 20, oncesaid safety shield 40 is in its fifth position. The safety shield 40 istherefore prevented to move back to a retracted position and the device1 is totally safe and can disposed of.

The device of the invention only requires a low force to be applied bythe user on the housing at the time of injection. For example the neededforce may be inferior to 5 Newton. Moreover, the device of the inventionreduces the risk of potential mis-use by the user. In particular, incase the user mis-uses the device of the invention, then the product isnot lost and the injection may be correctly and safely completed in theend.

1. A device (1) for automatic injection of a product (2) into aninjection site (4), said device being in one of a passive and activestate, triggering of injection being prevented when said device (1) isin its passive state and permitted when said device (1) is in its activestate, said device having: a housing (30, 30 a, 30 b) capable ofreceiving a container, the container being movable relative to thehousing between an initial position and an insertion position distallyspaced from the initial position, the container being in one of apassive state and an active state, movement of the container out of itsinitial position being prevented when the container is in its passivestate, and being permitted when the container is in its active state,and a safety shield (40) coupled with the housing (30) and being movablewith respect to the housing along a movement path having a predeterminedlength, the safety shield being movable between a first position and asecond position a first distance that is less than the predeterminedlength, and between the second position and a third position a seconddistance that is less than the predetermined length, first retainingmeans (60, 61, 54 a) for maintaining the container (20) in its passivestate, second retaining means (34 a, 81 b) for maintaining said device(1) in its passive state, said device (1) being characterized in that itfurther comprises: first deactivating means (50, 53) movable coincidentwith movement of the safety shield (40) the first distance to cooperatewith first retaining means (61, 54 a) so as to place the container (20)in the active state, and second deactivating means (50, 50 a) movablecoincident with movement of the safety shield (40) the second distanceto cooperate with second retaining means (34 a, 81 b) so as to place thedevice (1) in its active state, wherein part of the first and seconddeactivating means are formed on a sleeve (50) coupled to the safetyshield (40) and being received within said housing (30), the sleeve (50)moving in rotation and in translation with respect to the housing (30)when the safety shield (40) moves from its first position to its secondposition, the sleeve (50) moving in translation with respect to thehousing (30) when the safety shield (40) moves from its second positionto its third position.
 2. Device (1) according to claim 1, wherein saidfirst retaining means comprises a ring (60, 61) coupled with the housing(30), the ring (60) comprising at least one outer radial stop (61), thefirst deactivating means comprises a window (53) defined in the sleeve(50) and having an abutment surface (54 a), the outer radial stop (61)being engageable with the abutment surface (54 a) when the safety shield(40) is in its first position, and being disengageable from the abutmentsurface (54 a) when the safety shield (40) is moved from its firstposition to its second position.
 3. Device (1) according to claim 1,wherein the second retaining means comprises a radially deflectable leg(34) coupled to the housing (30), the second deactivating meanscomprises a projection (50 a), defined at a proximal end of said sleeve(50), the projection (50 a) being capable of deflecting the radiallydeflectable leg (34) from a rest position, in which the radiallydeflectable leg (34) maintains the device (1) in its passive state, to adeflected position, in which the device is in its active state,deflection of the radially deflectable leg (34) from its rest positionto its deflected position being caused by movement of the safety shield(40) from its second position to its third position.
 4. Device (1)according to claim 1, wherein it further comprises first guiding means(36, 36 a, 52) for causing the translational and rotational movement ofthe sleeve (50) when the safety shield (40) is moved from its firstposition to its second position, and second guiding means (36, 36 b, 52)for causing the translational movement of the sleeve (50) with respectto the housing (30) when the safety shield (40) is moved from its secondposition to its third position, the second guiding means (36, 36 b, 52)preventing the rotation of the sleeve (50) with respect to the housing(30) as the safety shield (40) is moved to its third position.
 5. Device(1) according to claim 4, wherein the first guiding means (36 a) definesthe first distance, and wherein the second guiding means (36 b) definesthe second distance.
 6. Device (1) according to claim 4, wherein saidfirst guiding means includes a peg (52) located on the sleeve (50) or onthe housing (30) and a first portion (36 a) of a cam (36) locatedrespectively on the housing (30) or on the sleeve (50) and in which thepeg (52) is engaged so as to be able to move slidingly within the cam(36), the first portion (36 a) of the cam (36) being inclined withrespect to the longitudinal axis A of the device (1), movement of thepeg (52 within the first portion (36 a) of the cam (36) causingtranslational and rotational movement of the sleeve (50) when the safetyshield (40) is moved from its first position to its second position. 7.Device (1) according to claim 6, wherein the second guiding meansinclude a second portion (36 b) of the cam (36), the second portion (36b) being longitudinal, the junction of the first and said secondportions (36 a, 36 b) of the cam (36) forming an elbow (36 c), themovement of the peg (52) within the second portion (36 b) of the cam(36) causing translational movement of the sleeve (50) when the safetyshield (40) is moved from its second position to its third position. 8.Device (1) according to claim 1, wherein said device (1) furthercomprises: first biasing means (100) coupled to the housing (30) forbiasing the container (20) toward the insertion position, the firstbiasing means (100) being in one of a compressed condition, in which thecontainer (20) is in its initial position, and an extended condition, inwhich the container (20) is in its insertion position, and thirdretaining means (31, 33, 71, 72) for maintaining the first biasing means(100) in its compressed condition, triggering means (80) being useractivatable for releasing the third retaining means (33, 72), once thedevice (1) is in its active state.
 9. Device (1) according to claim 8,wherein it further comprises first guiding means (36, 36 a, 52) forcausing the translational and rotational movement of the sleeve (50)when the safety shield (40) is moved from its first position to itssecond position, and second guiding means (36, 36 b, 52) for causing thetranslational movement of the sleeve (50) with respect to the housing(30) when the safety shield (40) is moved from its second position toits third position, the second guiding means (36, 36 b, 52) preventingthe rotation of the sleeve (50) with respect to the housing (30) as thesafety shield (40) is moved to its third position.
 10. Device (1)according to claim 9, wherein said first guiding means includes a peg(52) located on the sleeve (50) or on the housing (30) and a firstportion (36 a) of a cam (36) located respectively on the housing (30) oron the sleeve (50) and in which the peg (52) is engaged so as to be ableto move slidingly within the cam (36), the first portion (36 a) of thecam (36) being inclined with respect to the longitudinal axis A of thedevice (1), movement of the peg (52) within the first portion (36 a) ofthe cam (36) causing translational and rotational movement of the sleeve(50) when the safety shield (40) is moved from its first position to itssecond position.
 11. Device (1) according to claim 10, wherein thesecond guiding means include a second portion (36 b) of the cam (36),the second portion (36 b) being longitudinal, the junction of the firstand said second portions (36 a, 36 b) of the cam (36) forming an elbow(36 c), the movement of the peg (52) within the second portion (36 b) ofthe cam (36) causing translational movement of the sleeve (50) when thesafety shield (40) is moved from its second position to its thirdposition.
 12. Device (1) according to claim 11, wherein it comprisesreturn means (110) for biasing the safety shield (40) from its thirdposition to its second position after activation of the triggering means(80) but before the container (20) reaches its insertion position, thesecond guiding means (36 b, 52) causing the sleeve (50) to movetranslationally in the distal direction with respect to the housing (30)until the peg (52) comes in abutment with the elbow (56 c) formed at thejunction between the first portion (36 a) and second portion (36 b) ofthe cam (36).
 13. Device (1) according to claim 12, wherein said returnmeans comprise a spring (110) in a compressed condition when the safetyshield (40) is in its third position.
 14. Device (1) according to claim13, wherein said device (1) further comprises locking means (38, 56, 57)for preventing the sleeve (50) to rotate back with respect to thehousing (30) under the effect of said return means (110), the lockingmeans comprising a rotational stop (57) located on the sleeve (50) or onthe housing (30), the rotational stop (57) being engaged in abutmentagainst a longitudinal ridge (38) located on the housing (30) orrespectively on the sleeve (50), thereby preventing the rotation of thesleeve (50) with respect to the housing (50).
 15. Device (1) accordingto claim 14, wherein: the safety shield (40) being movable with respectto the container (20) from its third position, in which the tip (3 a) ofthe needle (3) does not extend beyond a distal end (40 a) of the safetyshield (40), to a fourth position, in which the tip (3 a) of the needle(3) extends beyond a distal end (40 a) of the safety shield (40), and toa fifth position, in which the tip (3 a) of the needle (3) does notextend beyond a distal end (40 a) of the safety shield (40), movement ofsaid safety shield (40) from its fourth position to its fifth positionbeing caused by release of a distal pressure exerted on said housing(40), said device (1) further comprises arresting means (41, 51, 51 a)for maintaining the safety shield (40) in its third position, in whichthe release of the distal pressure exerted on said housing (30) does notcause the safety shield (40) to move to its fifth position, thirddeactivating means (60, 62)) designed for deactivating the arrestingmeans when the safety shield (40) is in its fourth position secondbiasing means (110) coupled to the safety shield (40) for biasing thesafety shield (40) from its fourth position to its fifth position whendistal pressure exerted on the housing (30) is released.
 16. Device (1)according to claim 15, wherein the arresting means comprises a flexibleleg (41) located on the safety shield (40), the flexible leg (41) beingengaged on an abutment surface (51 a) located on the sleeve (50) so asto maintain the sleeve (50) coupled to the safety shield (40) when thesafety shield (40) is in its third position.
 17. Device (1) according toclaim 16, wherein the ring (60) being coupled to the container (20), thethird deactivating means comprises a distal skirt (62) located on thering (60), the distal skirt (62) cooperating with the flexible leg (41)located on the safety shield (40) so as to deflect the flexible leg(41), when the container (20) moves from its initial position to itsinsertion position, thereby causing the safety shield to be in itsfourth position.